[Protein metabolism during nephrotic syndrome. Experimental and clinical influence of dietary protein intake]

In adults, 12 to 14 g of albumin are synthesized daily. The same quantity is catabolized, essentially by the vascular endothelium and to a lesser degree in renal tubules. During nephrotic syndrome, contrary to what is observed in malnutrition conditions accompanied by hypoalbuminemia, hepatic synthesis is only moderately increased, whereas fractional catabolism is greater than normal. The increase in alimentary protein-intake, which has been proposed to restore the pool of albumin, raises hepatic albumin synthesis, but also its urinary losses, most likely by stimulation of the renin-angiotensin system. A reduction in protein rations lowers proteinuria and improves the hepatic abnormalities of nephrotic syndrome but its longterm nutritional consequences are poorly understood. The association of a converting enzyme inhibitor with a diet moderately restricted in protein content (1 g/kg/day) might constitute a therapeutic satisfactory solution.